shift = int(input())
text = input()
cipher = ''
for c in text:
    if 'A'<=c<='Z':
        cipher += chr((ord(c)-ord('A')+shift)%26+ord('A'))
    elif 'a'<=c<='z':
        cipher += chr((ord(c)-ord('a')+shift)%26+ord('a'))
    else:
        cipher += c
print(cipher)

